When cohesive force is stronger than the adhesive force: concave up meniscus, water forms droplets on surface
Inevitable manufacturing imperfections in optical fiber leads to birefringence, which is one cause of pulse broadening in fiber-optic communications. Such imperfections can be geometrical (lack of circular symmetry), due to stress applied to the optical fiber and/or due to bending of the fiber.
B. a nucleus with a positive charge.
